Sheet feed device for rotary duplicating machines



Oct. 14, 1952 E. RUTHSHAUSER SHEET FEED DEVICE FOR ROTARY DUPLICATING MACHINES Filed July 26, 1948 2 SHEETS.SHEET l INVENTOR. BY fi'dgarfiafzsfiaaser Oct. 14, 1952 E. RU'HSHAUEER 3,597

SHEET FEED DEVICE FOR ROTARY DUPLICATING MACHINES Filed July 26, 1948 2 SHEETS-SHEET 2 BY Mww a AGT Patented Oct. 14, 1952 SHEETFEEDDEVICE FOR ROTARY DUPLICATING MACHINES Edgar Rutishauser, Zurich, Switzerland Applicationfluly26, 1948;SerialNo. 40, 44

lns'witzerland March 24, 1947 e y teen (01. 101-432) V This invention relates to a rotary duplicating machine, more particularly a single-cylinder ro-. tary duplicator. My invention .is :especially .concerned with mechanism for accurately registering forms, drawings, charts, diagrams or the like on single-cylinder rotary duplicating machines.

A disadvantage in printing forms or the like on rotary duplicating machines is that the printed area does not assume the same position with respect to the edges of the sheetron all forms of one and the same series. For instance, the fact that the sheets in the pile of blank sheets do not lie upon each other quiteaccurately, or the pulling along of a sheet beneath the sheet fed into the machine, or play in the feeding mechanism may be the cause for misalignment in the printing position. The primary object of-my invention is to Overcome these difi iculties andto provide a mechanism which assures accurate register.

The mechanism of this 'invention may be used on single-cylinder rotary duplicating machines equipped with a cylinder movably carried in vertical guides, and a fixedly arranged pressin roller. The present invention provides three cams mounted on the shaft of the cylinder, each of these cams cooperating with a linkage, where by one cam controls a. forward and backward movement of a feeding or pushing roll, the second cam an oscillating movement of at'least'tw'o leadin rolls about their axes, and the thirdcam a movement to intermittently press at least two auxiliary pressing rolls against the lead-in rolls.

Since the printing cylinder can freely move upwardly and downwardly, it is desirable that the application of forces to, and movements of, the cams carried on thecylindershaft do not produce additional pressures directed upwardly or downwardly against the cylinder. This may be achieved by providing the points of contact of the follower rollers riding on the cams to be approximately in the horizontal plane of the axes of the cylinder and cams.

According to one feature of the invention, each paper lead-in roll is provided with an abutment, and it is further provided that the feeding distance imparted to a sheet to be printed by .the pushing roll is longer than the distance from the pile of blank sheets to the abutments on the lead in rolls. Thus, each sheet buckles upwardly upon its striking against the abutments, and the additional length produced bythis curvature will easily compensate for feeding irregularities. According to another feature of my resent invention, the axis of thepaper leadein rpllscan be changed with respect to the feeding direction ofthe sheets in order to correct oblique printing. I provide for this purpose anarmon the frame of the duplicating machine. This arm is arranged to swing, and the shaft of the lead-in rolls is eccentrically carried in the arm so that on moving of the arm the axis of the lead-inrolls performs an angular motion. The arm is provided with a clamping device for securing the shaft of the lead-in rolls in the desired position. In accordance with still another feature of this invention, the lead-in rolls cooperate with.the auxiliary pressing rolls in such a way that the latter, upon the striking of a sheet against the abutments of the lead-in. rolls, are pressed against the lead-in rolls to form pairs of rolls which feed the sheet like rolls of a rolling mill.

An important feature of my invention is a device to stop the machine whenever there is something wrong in the feed of sheets or when the pile of blank sheets is used up, and at the same time to provide that the pressing roller does not remain engaged with the cylinder in order that it be not soiled by the inked matrix. This device comprises a linkage cooperating with the linkage of the pushing roll, whereby the former linkage disengages the pressing roller which normally touches the cylinder. The disengaging linkage includes a member adapted to move forth and back and provided with an inclined s'urfacewhich cooperates with a swinging rod. This rod swings freely when sheets of paper are fed into the machine, whereas on interruption of the feed,'-it strikes against a guard which project'si'ntothe sheet feed path and serves as astop. The swing ing rod is thus arrested on one side in its move,- ment by the guard, and the portion running'on the inclined surface unco'uples a springloaded hook and moves the printing roller away from. the pressing position.

In case the duplicating machine is'drive'n by a motor, I provide that an electrical connection be interrupted and the motor stopped when the spring-loaded hook is uncoupled. It is desirable to provide for the three cams to be set in any position relative to the cyllnder. In this way the starts of the movements c'anbe retarded or advanced. For this purpose ,1 provide an arm fixedly connected to the cam's'an'd having a slot cooperating witha clamping device on one of the front faces of the cylinder. Thus; the three cams can be jointly either advanced or delayed. I To the accomplishment of the foregoing and qth 1-.-.Qbject which. wi h r ina t r. ap ean: my

invention consists in the mechanism elements and their relation one to the other, as are hereinafter more particularly described in the specification and sought to be defined in the claims.

The specification is accompanied by drawings in which:

Fig. 1 is a schematic perspective view of the device embodying features of my invention;

Fig. l a is a detail illustrating the support of the pressing roller in the printing position;

Fig. 2 is a detail illustrating the means for the disengagement f the pressing roller from the cylinder; and

Figs. 3 to 6 are explanatory of different phases in the operation of my mechanism.

Referring now in greater detail to the drawings, a printing cylinder I of a single-cylinder rotary duplicating machine is supported in slots 2 in the frame of the machine in a knownmanner. The shaft I of the cylinder carries three cams 3, 4 and 5. An arm 6 is solidly connected with these cams and is provided with a slot 8 which cooperates with a clamping devic 9 provided on the cylinder so that by turning of the arm the three cams may be turned and fixed jointly relative to the cylinder. The direction of the rotation. of the cylinder is indicated by the arrow A.

A lever having in a starlike arrangement three arms II], II, and I2 swings about a shaft I3 and cooperates with the cam 3. The arm III carries a cam follower roller I4 riding on the cam 3. The arm II is connected toa linkage I which in turn joins a feeding or pushing roll I to, shown in Figs. 3, 4 and 6. Connected. to the linkage I5 is a member I6 (see Figs. 1 and 2) which performs anoscillatingmovement and bears against a plate I 8. At the lower narrow side of the member I6 is aninclined surface I9 which moves along an end of a swinging rod 20.

Whenever a sheet 2I is moved by the pushing roll I5a onto the lead-in rolls 22a, 2212, a guard 24 is turned about its shaft 23 so as to allow the rod to swing freely. The guard member 24, if left alone, assumes due to its own weight the vertical position and projects through an aperture 25 in a sheet metal guide 28. If the paper feed stops, the guard 24 assumes the position shown in Fig. 1, and the swinging rod 26, while one of its ends strikes against the guard 24, the other end raises the member I6.

A hook 21, by means of an adjoining cross member Ifia, will also be pushed upwardly and lifted from the catch 28. Due to the pull of the spring 29 (Fig. 2), the hook will then be thrown backwardly into the dotted line position. At the end opposite to the catch 28, the hook is connected to a tilting lever 38 which carries the pressing roller 3|. On unlatching the hook 21 from the catch 28, the tilting lever 30 and. consequently the pressing roller 3| will be moved from the printing position into the dotted line position in which latter position the pressing roller is no longer in engagement with the cylinder I. The tilting lever 30 is provided with an extension 32 which in the dotted line position breaks the contact 33a, 33b of the motor circuit, the dotted line position of the extension. 32 conforming to the pressing roller when out of contact.

Referring to Fig. la, the pressing roller 3i is shown in the position in which it is in contact with the cylinder I, that is, the printing position. The shaft 3Ia of the roller 3I extends beyond the roller at each of its ends, and in the printing position it is fixedly supported in ball bearings 50 andBI. The line X-X indicates the position of 4 the tilting lever 30 in the printing position. The tilting lever is arranged to swing about the axis 52.

In a known way, the disengagement of the pressing roller from the cylinder cannot take place unless the cylinder is in a position where no impressional pressure is exerted on the cylinder, that is, where the ends of the matrix are fixed in afiat portion Ia of the cylinder. Such an arrangement is shown, for instance, in the Swiss Patent No. 241,218. During each revolution of the printing cylinder, the flat portion Ia comes to be adjacent the pressing roller 3| once. In this position there is no contact between the cylinder and the roller 3 I, making it possible for the latter to be moved away from the cylinder. The position of the fiat portion Ia with respect to the cams 3, 4 and 5 will be clearly seen from Figs. 3 to 5.

A cam follower roller 34 carried by a lever 35 cooperates with the cam 4. The lever 35 which is adapted to swing is provided with a curved rack 36 meshing with a gear 31 secured to the shaft 38' of the lead-in rolls 22a, 22b. A spring 39 holds the cam follower 34 above the gear 31 and the rack 36 in contact with the cam 4, thus causing the back movement of the lead-in rolls.

The lead-in rolls 22a, 22b have abutments 40 for the fed sheet 2|. (There can be more such lead-in rolls provided.) The lead-in stroke for a sheet is longer than the distance from the-pile of blank sheets to the abutments 40, urging each sheet to bulge, as shown in Figs. 1, 4 and 5. The lead-in rolls are knurled on their circumference to grip the sheet to be printed. When a sheet is in the curved position, auxiliary pressing rolls 42 are pressed against the lead-in rolls 22a, 22b, this being carried out from the cam 5 over the cam follower roller 43, levers 44 and 44a united by a spring 4311, and the shaft 45. There is an auxiliary pressing roll 42 to each lead-in roll. Thus, the sheet 2| comes to lie between pairs of rolls.

The feeding movement of the lead-in rolls is now started by the cam 4. The sheet of paper passes between the cylinder I and the pressing roller 3I, and this is done in perfect registry for each preceding and succeeding sheet, thanks to the abutments 40 provided on the lead-in rolls.

As soon as the sheet 2I has run through the printing cylinder I, the feed-in rolls 22a, 2212 change their rotational direction and due to the pull of the spring 39 return-to their original position in which the abutments 4H await another sheet.

The spring 41 holds the roller I4, provided on the arm IIl, against the cam 3.

In Figs. 3, 4, 5 and 6,. the positions of the cam follower rollers are shown. The roller I4 is the distance a, and the roller 34 the distance b, above the horizontal HH through the cylinder axis and the cam axis, and the roller 43 is the distance 0 below that horizontal.

Fig. 3 also shows the pushing roll I511 in its two end positions and its control by the cam 3.

Fig. 4 illustrates the moment in which the sheet of paper fed by the pushing roll I5 toward the lead-in rolls 22a, 22b strikes against the abut: ments of the latter rolls. The auxiliary" rolls, which are operated by the cam 5, are ready to be moved toward the lead-in rolls in the next moment to grip the paper sheet 2 I.

Fig. 5 illustrates the moment in which th leadin rolls and auxiliary rolls grip the sheet of paper, and the swinging strokeof the rack' 36 starts in the paper feeding direction. 'I

Fig. 6 illustrates the moment in which the sheet of paper leaves the lead-in rolls and auxiliary rolls, and the rack 36 at the end of the feeding movement. Fig. 6 also shows the paper sheet 2| being completely fed into the machine.

Both Figs. 5 and 6 indicate that the lever 35 and rack 38 are controlled by the cam 4, and the way the lead-in rolls are oscillated about their axes by means of the rack 36.

To correct oblique printing, the shaft 38 of the lead-in rolls is carried in an arm 48 which can be swung into different positions and which is provided with a clamping device 49. If the arm 48 is moved, the shaft 38 makes an angular motion around one of its bearings. In this way the direction of the sheets to be fed is changed and, thus, the position of the area to be printed on each sheet corrected.

It will be apparent that while I have shown and described my invention in a preferred form, many changes and modifications may be made without departing from the spirit of the invention defined in the following claims.

Iclaim:

1. Rotary duplicating machine comprising a single rotatable printing cylinder supported in vertical guides, a pressing roller fixedly supported in a tilting lever to be in engagement with the printing cylinder during normal operation and to be out of engagement with said cylinder on interruption of the feed of blank sheets to be printed, a reciprocating pushing roll successively feeding sheets toward said cylinder, the pushing roll feeding a single sheet per revolution of the cylinder, at least two lead-in rolls and at least two auxiliary rolls in front of the cylinder, each lead-in roll and each adjacent auxiliary roll forming a pair of rolls to receive a sheet supplied by the pushing roll and to feed same forward to be received between the printing cylinder and the pressing roller, the lead-in rolls being located below, and the auxiliary rolls being located above, the sheets passing therebetween, the lead-in rolls being mounted for angular displacements in their relation one to the other, and to oscillate about their axis, the auxiliary rolls being arranged in parallel relation to the printing cylinder, and to intermittently move in and out of operative engagement with the lead-in rolls, and means to operate the printing cylinder, pressing roller, pushing roll, lead-in rolls, and auxiliary rolls, said means including cams mounted on one side of the shaft of the cylinder, and an adjustable arm solidly connected to said cams to set said cams jointly relative to the cylinder.

2. In the duplicator according to claim 1, each lead-in roll being provided with an abutment on its periphery, said abutment projecting into the sheet feed path, the lead-in rolls being stationary during the feed of a blank sheet toward the abutments, the feeding movement of the pushing roll being longer than the distance from where the paper feed starts to said abutments, which causes buckling of the leading end of the sheet, the feeding action of the lead-in rolls and auxiliary rolls starting upon striking of the leading edge of the sheet fed against the abutments.

3. In the duplicator according to claim 1, an

arm provided on the frame of the machine and eccentrically carrying the shaft of the lead-in rolls, the shaft being supported to be angularly movable with respect to the axes of the printing cylinder and pressing roller by said arm, and a clamping device provided on the arm for fastening the shaft of the lead-in rolls in the desired position.

4. The duplicator according to claim 1, comprising means to disengage the pressing roller from the printing cylinder, said means being acted upon by the means to reciprocate the pushing roll and acting on the tiltable lever, the first named means including a swinging guard, a swinging rod, and a spring-loaded hook, said guard being supported below the sheet feed path to allow sheets of paper to be fed toward the printing cylinder and to allow the swinging rod to swing freely, as long as the paper feed continues, and to arrest the swinging rod on interruption of the feed, the spring-loaded book being connected with the tilting lever, one end of the swinging rod, on its arrest, uncoupling the springloaded hook, and said hook, upon its being uncoupled, tilting under the influence of its spring the tilting lever, thereby moving the pressing roller away from the printing position to an idle position.

5. The duplicator according to claim 1, comprising means to disengage the pressing roller from the printing cylinder, said means being acted upon by the means to reciprocate the pushing roll and acting on the tiltable lever, the first named means including a swinging guard, a swinging rod, a spring-loaded hook connected with the tilting lever to tilt the latter, and electric contact means positioned in the path of said hook, said guard being supported below the sheet feed path to allow sheets of paper to be fed toward the printing cylinder and to allow the swinging rod to swing freely, as long as the paper feed continues, and to arrest the swinging rod on interruption of the feed, one end of the swinging rod, on its arrest, uncoupling the spring-loaded hook, and said hook, upon its being uncoupled, tilting under the influence of its spring the tilting lever, thereby moving the pressing roller away from the printing position to an idle position, the spring-loaded hook, upon its being uncoupled, being adapted to actuate and break said electric contact.

6. The duplicator according to claim 1, wherein said adjustable arm is provided with a slot and cooperates with a clamping device on one of the front faces of the cylinder.

EDGAR RUTISHAUSER.

REFERENCES CITED 'The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,647,560 Chisholm et a1 Nov. 1, 1927 1,914,849 Davidson June 20, 1933 2,198,728 Horii Apr. 30, 1940 2,246,508 Davidson June 24, 1941 2,285,224 Nigra et al June 2, 1942 FOREIGN PATENTS Number Country Date 856,210 France June 7, 1940 

